Many types of sports equipment are useable only under certain conditions and/or in specific locales. Examples of such sports equipment include surfboards that are ridden at beaches and snow skis that are normally used at ski resorts. The beach and ski areas are often remotely located from the homes of those who use them, therefore the need for transporting sports equipment upon vehicles to these locations has long been recognized.
In the instance of bicycling, a rider will often desire to ride his or her bicycle in different areas without having to ride the bicycle to those areas. To facilitate the transportation of one or more bicycles, bicycle carriers mountable to passenger vehicles have been developed. The carriers are typically mountable to the rear end of a vehicle, however, the carriers may be configured to be mounted at other locations upon a vehicle as long as the location is convenient for loading the bicycles onto the carriers and neither the bicycles nor the carrier inconveniences the driver or obstructs visibility. Examples of such bicycle carriers are disclosed in U.S. Pat. No. 5,211,323 to Chimenti et al for a BICYCLE CARRIER ADAPTED TO BE MOUNTED ON THE BACK OF A VEHICLE and U.S. Pat. No. 5,363,996 to Raaber et al also entitled BICYCLE CARRIER ADAPTED TO BE MOUNTED ON THE BACK OF A VEHICLE, each of which is commonly owned together with the present invention and whose disclosures are expressly incorporated herein.
The carriers of the above referenced patents are mountable to the rear end of a carrying passenger vehicle. The carriers incorporate rigid mounting members that engage surfaces of the vehicle and clippable straps that when tightened secure the carrier to the vehicle. The carrier further includes support arms that extend away from the vehicle and upon which one or more bicycles may be secured. Once the carrier is properly configured for the particular vehicle upon which it is to be installed and it is secured thereupon, the orientation of the mounting members and support arms is fixed so that relative movement therebetween is prevented.
It has been discovered that the rigidly fixed orientation within a bicycle carrier as described hereinabove results in undue and potentially damaging forces or loads being generated within the structure of the carrier under certain circumstances during use. In some cases, these forces may be detrimentally communicated to the bicycle or other equipment carried upon the support arms. More typically, however, detrimental forces will be experienced at the cantilever connection of the support arm to the carrier. As with all cantilevers, the reaction forces at the cantilever connection required to resist moments caused by forces applied upon the cantilever at locations distal to said connection are greater than those distally applied forces. The amplification is due to the leveraging effect of the distance between the connection and the point at which the force is applied.
The forces are generated in the carrier when the carrying vehicle moves rapidly in the vertical direction. These vertical movements typically result from the vehicle passing over irregularities in the roadway being traveled. Obvious irregularities would include speed bumps and "chuck-holes", but any depression or rise in the roadway may result in the vehicle moving rapidly upward and/or downward depending upon the depth or height of the irregularity and the speed at which the vehicle is travelling. It has been found that forces induced within the carrier and imparted upon the equipment being carried may exceed several times that of gravity. While padding material has been provided between the carrier and the vehicle for protecting each from the other, the cushioning effect of the padding may not be sufficient to dampen the forces transferred therebetween.